SIST EN 14620-1:2024
(Main)Design and manufacture of site built, vertical, cylindrical, flat-bottomed tank systems for the storage of refrigerated, liquefied gases with operating temperatures between 0 °C and -196 °C - Part 1: General
Design and manufacture of site built, vertical, cylindrical, flat-bottomed tank systems for the storage of refrigerated, liquefied gases with operating temperatures between 0 °C and -196 °C - Part 1: General
This document is a specification for vertical, cylindrical tank systems, built on site, above ground and of which either the primary liquid container or the liquid tight barrier is made of steel. The secondary liquid container, if applicable, can be of steel or of concrete or a combination of both. A primary liquid container made of pre-stressed concrete is excluded from the scope of this document.
This document provides general requirements and specifies principles and application rules for the structural design of the tank system during construction, testing, commissioning, operation (accidental included), and decommissioning. This document applies to all tank system components attached to and located within the liquid, vapour, purge gas, membrane or membrane tank outer containers of the tank system. It does not address the requirements for ancillary equipment such as pumps, pumpwells, valves, instrumentation, external staircases and walkways, roof mounted platforms, external pipe supports, etc. The requirements for those components are covered by the relevant European Standards, structurally designed in accordance with Eurocodes where appropriate, and meeting applicable safety regulations.
This document also does not address tank system operating procedures unless specified for determination of the relevant resistance and protection criteria for the tank systems. It specifies minimum performance requirements for the tank system, tank system foundation and protection systems. From a process piping standpoint, the scope of this document is limited to the following boundaries:
a) the face of the first flange outside of the tank in bolted flanged connection;
b) the first threaded joint outside of the tank in threaded connection;
c) the first circumferential pipe welded joint outside of the tank in welding-end pipe connection, which does not have a flange.
This document is applicable to storage tank systems designed to store products, having an atmospheric boiling point below ambient temperature, in a dual phase, i.e. liquid and vapour. The equilibrium between liquid and vapour phases being maintained by cooling down the product to a temperature equal to, or just below, its atmospheric boiling point in combination with a slight overpressure in the storage tank system.
The maximum design pressure of the tank systems covered by this document is limited to 500 mbar. For higher pressures, reference can be made to EN 13445, Parts 1 to 5.
The operating range of the gases to be stored is between 0 °C and −196°C.
The tank systems covered by this document are used to store large volumes of hydrocarbon products, ammonia and other non-hydrocarbon gases with low temperature boiling points, generally called “Refrigerated Liquefied Gases” (RLGs). Typical products stored in the tank systems are: methane, ethane, propane, butane, ethylene, propylene, butadiene (this range includes the Liquefied Natural Gas (LNG’s) and Liquefied Petroleum Gas (LPG’s)), ammonia, nitrogen, oxygen and argon.
NOTE 1 Properties of the gases are given in Annex A.
The requirements of this document cannot cover all details of design and construction because of the variety of sizes and configurations that may be employed. Where complete requirements for a specific design are not provided, the intention is for the designer, subject to approval of the purchaser's authorized representative and of the regulatory body, to provide design and details that are as safe as those laid out in this document.
EN 14620 consists of multiple parts. This document specifies general requirements for the tank system concept, selection and general design considerations.
In case of a conflict between general requirements of this document and the requirements in other parts of EN 14620 related to a specific liquefied gas, the product-specific requirements set forth in the other parts prevail.
Auslegung und Herstellung standortgefertigter, stehender, zylindrischer Flachboden-Tanksysteme für die Lagerung von tiefkalt verflüssigten Gasen bei Betriebstemperaturen zwischen 0 °C und -196 °C - Teil 1: Allgemeines
Dieses Dokument behandelt stehende, zylindrische, standortgefertigte, oberirdische Tanksysteme, bei denen entweder der zur Aufnahme der Flüssigkeit vorgesehene Primärbehälter oder die flüssigkeitsdichte Sperre aus Stahl besteht. Der Sekundärbehälter, falls vorhanden, kann aus Stahl oder Beton, oder aus einer Kombination von beiden bestehen. Primärbehälter, die aus Spannbeton hergestellt werden, fallen nicht in den Anwendungsbereich dieses Dokuments.
Dieses Dokument enthält allgemeine Anforderungen und legt Grundsätze und Anwendungsregeln für die Bemessung des Tanksystems bei Bau, Prüfung, Inbetriebnahme, Betrieb (unbeabsichtigter Betrieb eingeschlossen) und Außerbetriebnahme fest. Dieses Dokument gilt für alle Bauteile, die an dem Tanksystem befestigt sind und sich in Flüssigkeit, Dampf, Spülgas, Membran oder Membrantank Außenbehältern des Tanksystems befinden. Anforderungen an Zusatzausrüstungen wie Pumpen, Pumpsonden, Ventile, Messgeräte, außenliegende Treppen und Laufstege, dachmontierte Plattformen, außenliegende Rohrhalterungen usw. werden nicht behandelt. Die Anforderungen an jene Bauteile werden in den betreffenden Europäischen Normen behandelt, ihre Bemessung erfolgt nach Eurocodes, wenn zutreffend, und es besteht Übereinstimmung mit anwendbaren Sicherheitsbestimmungen.
Dieses Dokument befasst sich auch nicht mit Betriebsverfahren für Tanksysteme, sofern dies nicht zur Bestimmung der relevanten Beständigkeits und Schutzkriterien für die Tanksysteme festgelegt ist. Es legt die Mindestanforderungen an das Tanksystem, das Fundament des Tanksystems und die Schutzsysteme fest. Aus Sicht der Prozessrohrleitungen ist der Anwendungsbereich dieses Dokuments auf die folgenden Grenzen beschränkt:
a) die Stirnseite des ersten Flansches außerhalb des Tanks bei verschraubten Flanschanschlüssen;
b) die erste Schraubverbindung außerhalb des Tanks bei einer Gewindeverbindung;
c) die erste umlaufende Rohrschweißnaht außerhalb des Tanks bei einem Rohranschluss mit Schweißende ohne Flansch.
Dieses Dokument ist anwendbar für Lagertanksysteme, die für die Lagerung von Produkten vorgesehen sind, die in der dualen Phase, d. h. in der Flüssigkeits und Dampfphase, bei atmosphärischem Druck einen Siedepunkt unterhalb der Umgebungstemperatur haben. Das Gleichgewicht zwischen Flüssigkeits und Dampfphase wird aufrechterhalten durch Abkühlung des Produkts auf eine Temperatur, die dem Siedepunkt bei atmosphärischem Druck oder einer etwas niedrigeren Temperatur entspricht, verbunden mit einem leichten Überdruck im Lagertanksystem.
Der maximale Auslegungsüberdruck für die in diesem Dokument behandelten Tanksysteme ist auf 500 mbar begrenzt. Für höhere Drücke kann auf EN 13445, Teil 1 bis Teil 5, Bezug genommen werden.
Der Betriebsbereich der zu lagernden Gase liegt bei 0 °C bis −196 °C.
Die in diesem Dokument behandelten Tanksysteme werden zur Lagerung großer Volumina von Kohlenwasserstoffprodukten, Ammoniak und anderen Nicht Kohlenwasserstoffgasen mit niedrigen Siedepunkten verwendet, die allgemein als „Tiefkalt verflüssigte Gase“ (RLG, en: refrigerated liquefied gases) bezeichnet werden. In den Tanksystemen werden üblicherweise Methan, Ethan, Propan, Butan, Ethylen, Propylen, Butadien (Flüssigerdgas (LNG, en: liquefied natural gas) und Flüssiggas (LPG, en: liquefied petroleum gas) sind eingeschlossen), Ammoniak, Stickstoff, Sauerstoff und Argon gelagert.
ANMERKUNG 1 Die Eigenschaften der Gase sind in Anhang A aufgeführt.
Da für diese Tanksysteme sehr viele Größenordnungen und Gestaltungsmöglichkeiten anwendbar sind, können durch die Anforderungen dieses Dokuments nicht alle Einzelheiten abgedeckt werden, die bei Auslegung und Bau der Tanksysteme zu beachten sind. Wenn für die Auslegung einer spezifischen Tankanlage keine vollständigen Anforderungen vorliegen, obliegt die Festlegung von
Conception et fabrication de réservoirs cylindriques fond plat, verticaux, construits sur site, destinés au stockage des gaz réfrigérés, liquéfiés, dont les températures de service sont comprises entre 0 °C et -196 °C - Partie 1 : Généralités
Le présent document donne les spécifications relatives aux réservoirs verticaux, cylindriques, construits sur site, situés au-dessus du niveau du sol et dont la cuve de liquide primaire ou la barrière étanche aux liquides est en acier. La cuve de liquide secondaire, le cas échéant, peut être en acier, en béton ou être une combinaison des deux. Le domaine d'application du présent document ne couvre pas les cuves de liquide primaires en béton précontraint.
Le présent document fournit des exigences générales et spécifie des principes et des règles d'application pour la conception structurelle du réservoir pendant la construction, les essais, la mise en service, le fonctionnement (y compris en cas d'accident) et la mise hors service. Le présent document s'applique à tous les constituants du réservoir qui sont fixés et qui sont situés à l'intérieur des cuves de liquide, récipients à vapeur, cuves de gaz de purge, réservoirs à membrane ou cuves externes du réservoir à membrane. Il n'aborde pas les exigences relatives aux équipements auxiliaires tels que les pompes, les puits de pompe, les vannes, l'instrumentation, les cages d'escalier externes, les passerelles, les plateformes montées sur le toit, les supports de tuyauterie externes, etc. Les exigences relatives à ces composants sont couvertes par des Normes européennes pertinentes, être conçus structurellement conformément aux Eurocodes le cas échéant, et satisfaire aux règles de sécurité applicables. Le réservoir doit être conçu pour supporter les charges dues aux constituants auxiliaires mentionnés, y compris les deux niveaux d'actions sismiques spécifiés au paragraphe 7.1.4 du présent document.
Le présent document n'aborde pas non plus les procédures de fonctionnement des réservoirs, à moins qu'elles ne soient spécifiées pour la détermination des critères de résistance et de protection pertinents pour les réservoirs. Il spécifie les exigences de performance minimale pour le réservoir, ses fondations et les dispositifs de protection. En ce qui concerne les tuyauteries du système, le domaine d'application du présent document est défini par les limites suivantes :
a) la face de la première bride à l'extérieur du réservoir en cas de raccord à bride boulonné ;
b) le premier joint fileté à l'extérieur du réservoir en cas de raccord fileté ;
c) le premier joint soudé de tuyauterie à l'extérieur du réservoir en cas de raccord avec extrémité à souder, sans bride.
Le présent document est applicable aux réservoirs de stockage d'un produit dont la température d'équilibre liquide vapeur à pression atmosphérique est inférieure à la température ambiante. L'équilibre entre les phases liquide et vapeur est maintenu par le refroidissement du produit à une température égale ou légèrement inférieure à sa température d'ébullition à pression atmosphérique, associée à une légère surpression dans le réservoir de stockage.
La pression maximale de conception des réservoirs couverts par le présent document est limitée à 500 mbar. Pour des pressions supérieures, il est possible de consulter l'EN 13445, Parties 1 à 5.
La plage de fonctionnement associée à la température des gaz à stocker est comprise entre 0 °C et -196 °C.
Les réservoirs couverts par le présent document sont utilisés pour le stockage de grands volumes de produits hydrocarbonés, d'ammoniac et d'autres gaz non hydrocarbonés se vaporisant à basse température, généralement appelés « gaz liquéfiés réfrigérés » (GLR). Les produits typiques stockés dans les réservoirs sont : le méthane, l'éthane, le propane, le butane, l'éthylène, le propylène, le butadiène (cette gamme de produits incluant les gaz naturels liquéfiés [GNL] et les gaz de pétrole liquéfiés [GPL]), l'ammoniac, l'azote, l'oxygène et l'argon.
NOTE 1 Les propriétés des gaz sont données dans l'Annexe A.
[...]
Konstruiranje in proizvodnja na mestu postavitve grajenih pokončnih, valjastih jeklenih posod z ravnim dnom za shranjevanje hlajenih utekočinjenih plinov z delovnimi temperaturami med 0 °C in –196 °C - 1. del: Splošno
Ta evropski standard je specifikacija za nadzemne pokončne, valjaste jeklene posode, grajene na mestu postavitve, s primarnim vsebnikom za tekočino ali pregrado, neprepustno za tekočino, izdelano iz jekla. Sekundarni vsebnik za tekočino, če obstaja, je lahko iz jekla ali betona oziroma kombinacije obojega. Primarni vsebnik za tekočino iz prednapetega betona ne spada na področje uporabe tega evropskega standarda.
Ta evropski standard določa načela in pravila uporabe za konstrukcijsko zasnovo »zadrževalnika« med gradnjo, preskušanjem, začetkom uporabe, delovanjem (vključno z neželenim delovanjem) in izločitvijo iz uporabe. Ne obravnava zahtev za pomožno opremo, kot so črpalke, črpalne postaje, ventili, cevovodi, instrumenti, stopnišča itd., razen če lahko vplivajo na konstrukcijsko zasnovo jeklenih posod. Ta evropski standard prav tako ne obravnava operativnih postopkov jeklenih posod.
Ta evropski standard se uporablja za vse komponente v jekleni posodi, pa tudi za tiste, ki so pritrjene nanjo in omogočajo dostop do nje. Določa minimalne zahteve glede zmogljivosti za jekleno posodo, njene temelje in zaščitne sisteme. Z vidika procesnih cevovodov je področje uporabe tega standarda omejeno na:
a) ploskev prve prirobnice zunaj jeklene posode v vijačno-prirobničnem priključku;
b) prvi navojni spoj zunaj jeklene posode v navojnem priključku;
c) prvi obodni cevni zvarni spoj zunaj jeklene posode v zavarjenem cevnem priključku brez prirobnice.
Ta evropski standard se uporablja za jeklene posode, namenjene shranjevanju dvofaznih (tj. v tekočem ali plinastem stanju) izdelkov z atmosferskim vreliščem, nižjim od temperature okolja. Ravnovesje med tekočim in plinastim stanjem se vzdržuje z ohlajanjem izdelka na temperaturo, ki je enaka ali tik pod atmosferskim vreliščem, ter rahlim nadtlakom v jekleni posodi za shranjevanje.
Največji konstrukcijski tlak jeklenih posod, zajetih v tem evropskem standardu, je omejen na 500 mbar. Za višji tlak se je mogoče sklicevati na standard EN 13445 (1. do 5. del).
Delovno območje plinov za shranjevanje je med 0 °C in –196 °C.
Jeklene posode, zajete v tem evropskem standardu, se uporabljajo za shranjevanje velike količine ogljikovodikovih proizvodov, amoniaka in drugih plinov, ki ne vsebujejo ogljikovodikov, z nizkim vreliščem, v splošnem imenovane »hlajeni utekočinjeni plini« (RLG). V jeklenih posodah se običajno shranjujejo metan, etan, propan, butan, etilen, propilen, butadien (to vključuje utekočinjeni zemeljski plin (LNG) in utekočinjeni naftni plin (LPG)), amoniak, dušik, kisik in argon.
Zaradi različnih velikosti in konfiguracij, ki se lahko uporabljajo, zahteve tega evropskega standarda ne morejo zajemati vseh podrobnosti načrtovanja in izdelave. Če zahteve za določeno zasnovo niso v celoti podane, naj bi načrtovalec, ob odobritvi pooblaščenega predstavnika kupca, zagotovil zasnovo in podrobnosti, ki so enako varne kot tiste, določene v tem evropskem standardu.
Ta evropski standard določa splošne zahteve za koncept jeklenih posod, izbiro in splošne vidike načrtovanja.
Posebne zahteve za tekoči dušik, tekoči kisik in tekoči argon so zajete v 6. delu, posebne zahteve za brezvodni amoniak pa v 7. delu tega evropskega standarda. V primeru neskladja med zahtevami iz tega dela in zahtevami z enako vsebino iz 6. in 7. dela imajo prednost zahteve, določene v 6. in 7. delu.
General Information
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Standards Content (Sample)
SLOVENSKI STANDARD
01-september-2024
Nadomešča:
SIST EN 14620-1:2007
Konstruiranje in proizvodnja na mestu postavitve grajenih pokončnih, valjastih
jeklenih posod z ravnim dnom za shranjevanje hlajenih utekočinjenih plinov z
delovnimi temperaturami med 0 °C in –196 °C - 1. del: Splošno
Design and manufacture of site built, vertical, cylindrical, flat-bottomed tank systems for
the storage of refrigerated, liquefied gases with operating temperatures between 0 °C
and -196 °C - Part 1: General
Auslegung und Herstellung standortgefertigter, stehender, zylindrischer Flachboden-
Tanksysteme für die Lagerung von tiefkalt verflüssigten Gasen bei Betriebstemperaturen
zwischen 0 °C und -196 °C - Teil 1: Allgemeines
Conception et fabrication de réservoirs cylindriques fond plat, verticaux, construits sur
site, destinés au stockage des gaz réfrigérés, liquéfiés, dont les températures de service
sont comprises entre 0 °C et -196 °C - Partie 1 : Généralités
Ta slovenski standard je istoveten z: EN 14620-1:2024
ICS:
23.020.10 Nepremične posode in Stationary containers and
rezervoarji tanks
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
EN 14620-1
EUROPEAN STANDARD
NORME EUROPÉENNE
May 2024
EUROPÄISCHE NORM
ICS 23.020.10 Supersedes EN 14620-1:2006
English Version
Design and manufacture of site built, vertical, cylindrical,
flat-bottomed tank systems for the storage of refrigerated,
liquefied gases with operating temperatures between 0 °C
and -196 °C - Part 1: General
Conception et fabrication de réservoirs cylindriques Auslegung und Herstellung standortgefertigter,
fond plat, verticaux, construits sur site, destinés au stehender, zylindrischer Flachboden-Tanksysteme für
stockage des gaz réfrigérés, liquéfiés, dont les die Lagerung von tiefkalt verflüssigten Gasen bei
températures de service sont comprises entre 0 °C et - Betriebstemperaturen zwischen 0 °C und -196 °C - Teil
196 °C - Partie 1 : Généralités 1: Allgemeines
This European Standard was approved by CEN on 16 March 2024.
CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references
concerning such national standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN
member.
This European Standard exists in three official versions (English, French, German). A version in any other language made by
translation under the responsibility of a CEN member into its own language and notified to the CEN-CENELEC Management
Centre has the same status as the official versions.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway,
Poland, Portugal, Republic of North Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and
United Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2024 CEN All rights of exploitation in any form and by any means reserved Ref. No. EN 14620-1:2024 E
worldwide for CEN national Members.
Contents Page
European foreword . 4
1 Scope . 6
2 Normative references . 7
3 Terms and definitions . 8
3.1 General. 8
3.2 Components . 9
3.3 Design . 12
3.4 Operation . 13
3.5 Other . 14
4 Concept selection . 14
4.1 Types of tank systems . 14
4.1.1 General. 14
4.1.2 Single containment system . 14
4.1.3 Double containment system . 15
4.1.4 Full containment system . 15
4.1.5 Membrane containment system . 15
4.2 Risk assessment based tank system selection . 21
4.2.1 General. 21
4.2.2 Site selection . 21
4.2.3 Key drivers for tank system selection . 21
4.2.4 Hazard identification . 22
4.2.5 Risk assessment methodology . 24
4.2.6 Changes . 25
4.2.7 Determination of actions . 25
5 Quality assurance and quality control . 26
6 Health, safety and environment . 26
6.1 Health, safety . 26
6.2 Environmental . 26
7 General design considerations. 26
7.1 General. 26
7.1.1 Responsibilities . 26
7.1.2 Performance criteria . 27
7.1.3 Limit state and allowable stress theory . 27
7.1.4 Earthquake design . 28
7.1.5 Tightness . 29
7.1.6 Permanent openings in the primary, secondary, purge gas, warm vapour containers
and membrane containment system . 30
7.1.7 Attachments to primary and secondary containers and membrane containment
system . 32
7.1.8 Liquid levels and capacities . 32
7.1.9 Cool-down . 33
7.1.10 Foundation . 34
7.1.11 Foundation heating system . 35
7.1.12 Thermal Protection System (TPS) of concrete secondary liquid container . 36
7.1.13 Bund wall . 36
7.1.14 Lightning . 36
7.1.15 Vertical anchors . 36
7.2 Protection systems . 37
7.2.1 Instrumentation . 37
7.2.2 Pressure and vacuum protection . 39
7.2.3 Fire protection . 40
7.3 Actions (loadings). 40
7.3.1 General . 40
7.3.2 Normal actions . 40
7.3.3 Accidental actions. 42
7.3.4 Action combinations . 44
7.3.5 Loads from ancillary components . 44
8 Inspection and maintenance . 44
9 Marking and documentation . 44
9.1 Nameplates . 44
9.2 Certification . 47
9.3 Handover documentation . 47
Annex A (informative) Physical properties of gases . 48
Annex B (normative) Design information . 49
Annex C (normative) Seismic analysis . 51
Annex D (informative) Tank heating system . 55
Annex E (informative) Recommendations for geotechnical investigations and seismic hazard
evaluation . 57
Annex F (informative) Guidance for duties and responsibilities between parties . 63
Bibliography . 65
European foreword
This document (EN 14620-1:2024) has been prepared by Technical Committee CEN/TC 265 “Metallic
tanks for the storage of liquids”, the secretariat of which is held by BSI.
This European Standard shall be given the status of a national standard, either by publication of an
identical text or by endorsement, at the latest by November 2024, and conflicting national standards shall
be withdrawn at the latest by November 2024.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. CEN shall not be held responsible for identifying any or all such patent rights.
This document supersedes EN 14620-1:2006.
— general editorial update;
— standard boundaries are defined in the scope and applicability extended to −196 °C;
— terms and definitions adjusted;
— normative references updated;
— description of various tank system concepts updated;
— risk assessment requirements improved;
— liquid levels and capacities clarified;
— foundation requirements updated and allowable foundation settlement requirements added;
— secondary containment design requirements clarified;
— earthquake requirements clarified;
— new chapter on marking and documentation added;
— new informative annex with recommendation for geotechnical investigation and seismic hazard
evaluation added;
— design requirements for permanent openings, improved.
A list of all parts in the EN 14620 series, “Design and manufacture of site built, vertical, cylindrical, flat-
bottomed tank systems for the storage of refrigerated, liquefied gases with operating temperatures between
0 °C and −196 °C”, can be found on the CEN website.
Any feedback and questions on this document should be directed to the users’ national standards body.
A complete listing of these bodies can be found on the CEN website.
According to the CEN-CENELEC Internal Regulations, the national standards organisations of the
following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia,
Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland,
Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and the United
Kingdom.
1 Scope
This document is a specification for vertical, cylindrical tank systems, built on site, above ground and of
which either the primary liquid container or the liquid tight barrier is made of steel. The secondary liquid
container, if applicable, can be of steel or of concrete or a combination of both. A primary liquid container
made of pre-stressed concrete is excluded from the scope of this document.
This document provides general requirements and specifies principles and application rules for the
structural design of the tank system during construction, testing, commissioning, operation (accidental
included), and decommissioning. This document applies to all tank system components attached to and
located within the liquid, vapour, purge gas, membrane or membrane tank outer containers of the tank
system. It does not address the requirements for ancillary equipment such as pumps, pumpwells,
valves, instrumentation, external staircases and walkways, roof mounted platforms, external pipe
supports, etc. The requirements for those components are covered by the relevant European Standards,
structurally designed in accordance with Eurocodes where appropriate, and meeting applicable safety
regulations.
This document also does not address tank system operating procedures unless specified for
determination of the relevant resistance and protection criteria for the tank systems. It specifies
minimum performance requirements for the tank system, tank system foundation and protection
systems. From a process piping standpoint, the scope of this document is limited to the following
boundaries:
a) the face of the first flange outside of the tank in bolted flanged connection;
b) the first threaded joint outside of the tank in threaded connection;
c) the first circumferential pipe welded joint outside of the tank in welding-end pipe connection, which
does not have a flange.
This document is applicable to storage tank systems designed to store products, having an atmospheric
boiling point below ambient temperature, in a dual phase, i.e. liquid and vapour. The equilibrium between
liquid and vapour phases being maintained by cooling down the product to a temperature equal to, or
just below, its atmospheric boiling point in combination with a slight overpressure in the storage tank
system.
The maximum design pressure of the tank systems covered by this document is limited to 500 mbar. For
higher pressures, reference can be made to EN 13445, Parts 1 to 5.
The operating range of the gases to be stored is between 0 °C and −196 °C.
The tank systems covered by this document are used to store large volumes of hydrocarbon products,
ammonia and other non-hydrocarbon gases with low temperature boiling points, generally called
“Refrigerated Liquefied Gases” (RLGs). Typical products stored in the tank systems are: methane, ethane,
propane, butane, ethylene, propylene, butadiene (this range includes the Liquefied Natural Gas (LNG’s)
and Liquefied Petroleum Gas (LPG’s)), ammonia, nitrogen, oxygen and argon.
NOTE Properties of the gases are given in Annex A.
The requirements of this document cannot cover all details of design and construction because of the
variety of sizes and configurations that may be employed. Where complete requirements for a specific
design are not provided, the intention is for the designer, subject to approval of the purchaser's
authorized representative and of the regulatory body, to provide design and details that are as safe as
those laid out in this document.
EN 14620 consists of multiple parts. This document specifies general requirements for the tank system
concept, selection and general design considerations.
In case of a conflict between general requirements of this document and the requirements in other parts
of EN 14620 related to a specific liquefied gas, the product-specific requirements set forth in the other
parts prevail.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content
constitutes requirements of this document. For dated references, only the edition cited applies. For
undated references, the latest edition of the referenced document (including any amendments) applies.
EN 1990:2023, Eurocode — Basis of structural and geotechnical design
EN 1991-1-3:2003, Eurocode 1 — Actions on structures — Part 1-3: General actions - Snow loads
EN 1991-1-4:2005, Eurocode 1: Actions on structures — Part 1-4: General actions - Wind actions
EN 1991-1-6:2005, Eurocode 1 — Actions on structures Part 1-6: General actions - Actions during
execution
EN 1997-1:2004, Eurocode 7: Geotechnical design — Part 1: General rules
EN 1998-1:2004, Eurocode 8: Design of structures for earthquake resistance — Part 1: General rules,
seismic actions and rules for buildings
EN 1998-4:2006, Eurocode 8 — Design of structures for earthquake resistance — Part 4: Silos, tanks and
pipelines
EN 1998-5:2004, Eurocode 8: Design of structures for earthquake resistance — Part 5: Foundations,
retaining structures and geotechnical aspects
EN 14620-2:2006, Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for
the storage of refrigerated, liquefied gases with operating temperatures between 0 °C and -165 °C — Part
2: Metallic components
EN 14620-3:2006, Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for
the storage of refrigerated, liquefied gases with operating temperatures between 0 °C and -165 °C — Part
3: Concrete components
EN 14620-4:2006, Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for
the storage of refrigerated, liquefied gases with operating temperatures between 0 °C and -165 °C — Part
4: Insulation components
EN 14620-5:2006, Design and manufacture of site built, vertical, cylindrical, flat-bottomed steel tanks for
the storage of refrigerated, liquefied gases with operating temperatures between 0 °C and -165 °C — Part
5: Testing, drying, purging and cool-down
EN ISO 28300:2008, Petroleum, petrochemical and natural gas industries — Venting of atmospheric and
low-pressure storage tanks (ISO 28300:2008)
As impacted by EN 1993-1-3:2003/AC:2009 and EN 1993-1-3:2003/A1:2015.
As impacted by EN 1993-1-4:2005/A1:2010 and EN 1993-1-4:2005/AC:2010.
As impacted by EN 1991-1-6:2005/AC:2013.
As impacted by EN 1997-1:2004/A1:2013.
As impacted by EN 1998-1:2004/AC:2009 and EN 1998-1:2004/A1:2013.
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at https://www.iso.org/obp
— IEC Electropedia: available at https://www.electropedia.org/
3.1 General
3.1.1
double containment tank system
liquid and vapour tight primary container, which itself is a single containment tank system, built inside a
liquid tight secondary container
Note 1 to entry: See 4.1.3.
3.1.2
full containment tank system
liquid tight primary container and a liquid and vapour tight secondary container, which together form an
integrated storage tank system
Note 1 to entry: See 4.1.4.
Note 2 to entry: For an open top primary container the secondary container contains the vapour in normal
operation. The secondary container ensures controlled venting in case of the primary container leakage for any
primary container configuration.
3.1.3
hazard
event having the potential to cause harm, including ill health and injury, damage to property, products or
the environment, production losses or increased liabilities
3.1.4
membrane containment tank system
metallic liquid barrier (membrane) together with load bearing thermal insulation and a self- supporting
membrane tank outer container jointly forming an integrated, composite system
Note 1 to entry: See 4.1.5.
3.1.5
risk
measure of the combination (usually the product) of the probability or frequency of occurrence of a
defined hazard and the magnitude of the consequences of the occurrence
[SOURCE: EN 1991-1-7:2006/A1:2014, 1.5.13]
3.1.6
single containment tank system
tank system having only one self-supporting steel tank (primary liquid container) capable of storing
liquid product
Note 1 to entry: The product vapour is contained by the primary container or by means of a metallic outer tank. See
also 4.1.2.
3.1.7
tank system
equipment designed for the purpose of storing refrigerated liquefied gas (RLG) consisting of one or more
containers together with all other necessary components within the scope of this document
3.2 Components
3.2.1
annular space
space between the primary liquid container and the outer tank
3.2.2
base slab
continuous concrete base supporting the tank system (either on the ground or elevated)
3.2.3
bund wall
low construction of earth or concrete surrounding the storage tank system at a considerable distance to
contain spilled liquid
3.2.4
foundation
elements of the construction that comprise the base slab, ring-wall, pile system or other engineered
elements required to support the tank system and contents
3.2.5
insulation space
volume containing insulation material in the tank system annular space, and between the tank system
bottoms or roofs
3.2.6
insulation system
component of the tank system consisting of a complete package of insulation material and, when
applicable, components for the insulation material fixing and protection to limit heat in-leak in the tank
system and maintain RLG in the liquefied state at pressure close to atmospheric
3.2.7
liner
metallic plate installed against the inside of the concrete outer tank, impervious to product vapour and
water vapour
3.2.8
liquid barrier
parts of the tank system which prevents direct contact of refrigerated liquefied gas (RLG) with other
components of the system but does not have structural capabilities to independently carry liquid load
3.2.9
load bearing insulation
thermal insulation with special properties capable of transferring loads to the appropriate load bearing
structures
3.2.10
membrane
part of a membrane containment tank system that, during normal operation, forms a liquid and vapour
tight barrier
3.2.11
membrane tank outer container
the part of a membrane containment tank system that carries liquid and pressure loads during normal
operation and may contain liquid in the event of liquid leakage from the membrane
Note 1 to entry: The membrane tank outer container type M-CC ensures controlled venting in the case of a
membrane leakage.
3.2.12
moisture barrier
layer to prevent entry of water vapour and other atmospheric gases into the insulation or into the outer
tank
3.2.13
outer tank
self-supporting cylindrical secondary liquid container, purge gas container or warm vapour container
made of steel or concrete
3.2.14
pressure relief valve
valve designed to open and relieve excess pressure and to reclose and prevent the further flow of fluid
out after normal conditions have been restored
3.2.15
primary liquid container
part of a single, double or full containment tank system that contains the liquid during normal operation
3.2.16
purge gas container
parts of a tank system that contain only purge gas and are not expected to function after exposure to
product temperature
3.2.17
ringbeam
circular support under the shell of the tank
3.2.18
roof
structure on top of a shell or wall containing the vapour pressure and sealing off the contents from the
atmosphere
3.2.19
secondary liquid container
part of a double or a full containment tank system that contains the liquid in the event of leakage from
the primary liquid container
3.2.20
self-supporting tank
container designed to independently carry the liquid and the vapour pressure loads as well as the
external loads, where applicable
3.2.21
shell
metallic vertical cylinder
3.2.22
suspended roof
structure for supporting the internal insulation of the roof
3.2.23
Thermal Protection System
TPS
thermally insulating and liquid tight system to protect the concrete secondary liquid container or the
membrane tank outer container against low temperatures in the event of leakage through primary liquid
container or the membrane respectively
Note 1 to entry: The TPS is a part of a secondary containment system.
Note 2 to entry: Examples include bottom and bottom corner (see also 7.1.12).
3.2.24
vacuum relief valve
valve designed to open and relieve negative pressure (vacuum) and then reclose to prevent further inflow
of fluid after normal conditions have been restored
3.2.25
vapour barrier
impermeable layer to prevent escape of product vapours from the tank system
3.2.26
vapour container
part of a single, double, full containment or membrane tank systems that contains the vapour during
normal operation
3.2.27
warm vapour container
parts of a tank system that contain product vapour, and prevent entry of water vapour and other
atmospheric gases during normal operation but are not expected to function once exposed to refrigerated
product temperature
Note 1 to entry: This includes fixed roofs over suspended insulation roof and the outer container of a double wall,
open top single containment tank system.
3.3 Design
3.3.1
action
mechanical influence on a structure, or a structural member, exerted directly or indirectly from its
environment
Note 1 to entry: See EN 1990:2023, 3.1.3.2, 3.1.3.3, 3.1.3.5 to 3.1.3.10 for definitions of specific actions.
[SOURCE: EN 1990:2023, 3.1.3.1]
3.3.2
design metal temperature
minimum temperature for which the metal component is designed
3.3.3
design negative pressure
maximum permissible negative pressure (vacuum)
3.3.4
design pressure
maximum permissible pressure
3.3.5
design service life
assumed period for which a structure or part of it is to be used for its intended purpose with anticipated
maintenance but without major repair being necessary
[SOURCE: EN 1990:2023, 3.1.2.11]
3.3.6
lodmat
lowest one-day average ambient temperature
Note 1 to entry: The average temperature is half the sum of the maximum and minimum temperature.
3.3.7
maximum design liquid level
DLL
maximum liquid level which shall not be exceeded and is used for the static design
3.3.8
minimum design temperature
assumed temperature of the product, specified by the purchaser, for which the tank system is designed
Note 1 to entry: This temperature can be lower than the actual product temperature.
3.3.9
Operating Basis Earthquake
OBE
maximum earthquake event for which no damage is sustained and restart and safe operation can
continue
3.3.10
pneumatic test pressure
air pressure in the tank system during testing
3.3.11
Safe Shutdown Earthquake
SSE
maximum earthquake event for which the essential functions and mechanisms for safety are designed to
be preserved
Note 1 to entry: Permanent damage can be accepted without the loss of liquid and vapour containment. The tank
system would not remain in operation without a detailed examination and structural assessment.
3.4 Operation
3.4.1
boil-off
process of vaporization of refrigerated liquid by heat conducted through the insulation surrounding the
storage tank system
3.4.2
freeboard
margin on tank system wall height in cold condition to prevent the overfill, to allow for tilting settlements
and to accommodate seismic sloshing wave
3.4.3
maximum design liquid capacity
gross capacity
volume between the maximum design liquid level and the tank bottom
3.4.4
maximum normal operating level
maxNOL
maximum liquid level maintained during normal operation of the tank system to meet the requirements
specified by the purchaser
3.4.5
minimum normal operating level
minNOL
minimum liquid level maintained during normal operation of the tank system to meet the requirements
specified by the purchaser
3.4.6
net capacity
net working capacity
liquid volume between the maximum and the minimum normal operating levels
3.4.7
rollover
uncontrolled mass movement of stored liquid, correcting an unstable state of stratified liquids of different
densities and resulting in a significant evolution of product vapour
3.4.8
set pressure
pressure at which the pressure relief device first opens
3.5 Other
3.5.1
contractor
company contracted to supply a tank system or services as specified by the purchaser
3.5.2
purchaser
company which gives an order to the contractor for the supply of a tank system or services
4 Concept selection
4.1 Types of tank systems
4.1.1 General
Several different tank system concepts for RLG storage exist. The storage systems are differentiated
based on the ability of each storage system to contain product liquid and/or vapour releases due to both
internal and external hazards. Due to rapid boiling of refrigerated liquids when exposed to ambient
conditions, a liquid release from a tank system to the surrounding ground generates a significant amount
of uncontrolled cold vapours and results in a reduction in surface temperature of the surroundings. As a
result, liquid releases are generally more dangerous than just vapour releases.
Four basic storage tank systems are described below which, due to a number of factors including
materials of construction, configuration, structural redundancy and protective measures vary in their
ability to resist hazards and contain product release.
While each storage system can ensure the safe RLG storage, selection of a storage system most suitable
for the specific site and the project shall be determined via a detailed risk assessment. Basic requirements
for the risk assessment process for the storage system selection are provided in 4.2.
The tank configurations described in 4.1.2 to 4.1.5 are provided in Figures 1 to 4 as examples only. Other
configurations are acceptable providing that requirements toward the tank concepts described in 4.1.2
to 4.1.5 are satisfied.
4.1.2 Single containment system
A single containment tank system shall consist of only one container to store the liquid product (primary
liquid container). This primary liquid container shall be a self-supporting, steel, cylindrical tank.
The product vapours shall be contained by:
— either the steel dome roof of the container; or
— when the primary liquid container is an open top cup, by a gas-tight metallic outer tank
encompassing the primary liquid container, but being only designed to contain the product vapours
and to hold and protect the thermal insulation.
NOTE 1 Depending on the options taken for vapour containment and thermal insulation; several types of single
containment tank systems exist.
NOTE 2 For examples of single containment tank systems, see Figure 1.
4.1.3 Double containment system
A double containment tank system shall consist of a liquid and vapour tight primary container, which
itself is a single containment tank system, built inside a liquid tight secondary container.
The wall and the concrete foundation (or the liquid tight bottom) for the secondary liquid container shall
be designed to hold all the liquid contents of the primary container in case it leaks.
NOTE 1 The secondary container is open at the top and, therefore, does not prevent the escape of product
vapours.
The space between primary and secondary container shall be determined during the risk assessment and
can be covered by a “rain shield” to prevent the entry of rain, snow, dirt etc.
NOTE 2 For examples of double containment tank systems, see Figure 2.
4.1.4 Full containment system
A full containment tank system shall consist of a primary liquid container and a secondary liquid
container, which together form an integrated storage tank system. Both primary and secondary liquid
container are designed to be liquid tight. The primary liquid container shall be a self-standing steel, single
shell tank, holding the liquid product.
The primary liquid container shall either be:
— open at the top, in which case it does not contain the product vapours; or
— equipped with a dome roof so that the product vapours are contained.
The secondary liquid container shall be a self-supporting steel or concrete tank equipped with a dome
roof and designed to combine the following functions:
— in normal service: to provide the primary vapour containment of the tank system (in the case of an
open top primary liquid container) and to hold the thermal insulation of the primary liquid container;
— in case of leakage of the primary liquid container: to contain all liquid product. Some vapour escape
due to vapour permeability of the secondary liquid container is acceptable. Venting release is
acceptable but shall be controlled (pressure relief system).
Full containment tank systems with thermal insulation placed externally to the secondary container are
also covered by these requirements.
NOTE For examples of full containment tank systems, see Figure 3.
4.1.5 Membrane containment system
A membrane containment tank system shall consist of a metallic liquid barrier (membrane) together with
load bearing thermal insulation and a self-supporting membrane tank outer container jointly forming an
integrated, composite system.
The liquid barrier shall be liquid tight and vapour tight during normal operation. The product vapour
shall be contained by the tank system roof. The roof can be either a similar composite system or a gas-
tight dome roof and insulation on a suspended roof.
All hydrostatic loads and other loadings on the membrane shall be transferred via the load-bearing
insulation onto the membrane tank outer container.
The membrane tank outer container shall be designed to structurally resist all loads for both normal and
abnormal conditions. It also acts as a purge gas container. It can be either made of concrete or metal, or
a combination of both. In the case of a concrete outer container, a moisture barrier shall be applied on
the concrete inner face.
Two types of membrane containment systems exist, according to the ability of the membrane tank outer
container to contain the product in case of a leakage of the membrane:
— Type M-1: The membrane tank outer container is not designed to contain the product in case of
leakage of the membrane. No Thermal Protection System is provided for the concrete membrane
tank outer container with a monolithic wall-to-base joint.
NOTE 1 For an example of an M-1 tank system see Figure 4 a).
— Type M-CC: the membrane tank outer container is designed to contain the product in case of leakage
of the membrane while serving as a purge gas container during normal operation. In case of
membrane leakage, some product vapour escape due to vapor permeability of membrane tank outer
container is acceptable. Venting release is acceptable but shall be controlled (pressure relief system).
When the membrane tank outer container is made of concrete a Thermal Protection System may be
provided as specified in 7.1.11.
NOTE 2 For an example of an M-CC tank system see Figure 4 b).
a)
b)
Key
1 primary liquid container (steel) 8 roof (steel)
3 load bearing insulation (bottom) 9 external shell insulation
4 foundation 10 external moisture barrier
5 foundation heating system 11 loose fill insulation
6 flexible insulating seal 12 warm vapour container
7 suspended roof (insulated) 13 bund wall
Figure 1 — Examples of single containment tank system
a)
b)
Key
1 primary liquid container (steel) 8 roof (steel)
2 secondary liquid container (steel or pre-stressed concrete) 9 external insulation
3 load bearing insulation (bottom) 10 external moisture barrier
4 foundation 11 loose fill insulation
5 foundation heating system 12 warm vapour container
6 flexible insulating seal 13 cover (rain shield)
7 suspended roof (insulated)
Figure 2 — Examples of double containment tank system
a)
b)
Key
1 primary liquid container (steel) 7 suspended roof (insulated)
2 secondary liquid container (steel) 8 roof (carbon steel)
3 load bearing insulation (bottom) 9 loose fill insulation
4 Foundation 10 concrete roof
5 foundation heating system 11 pre-stressed concrete secondary liquid container
6 flexible insulating seal 12 TPS system (if applicable)
Figure 3 — Examples of full containment tank system
a) Membrane containment tank system type M-1
b) Membrane containment tank system type M-CC
Key
1 membrane 8 type M-CC membrane tank outer container roof
(concrete or steel)
2 type M-CC membrane tank outer container (pre- 9 load bearing insulation (wall)
stressed concrete or steel)
3 load bearing insulation (bottom) 10 type M-1 membrane tank outer container roof (steel)
4 foundation 11 type M-1 membrane tank outer container (steel)
5 foundation heating system 12 bund wall
6 flexible insulating seal 13 TPS System (if applicable)
7 suspended roof (insulated)
Figure 4 — Examples of membrane containment tank system
4.2 Risk assessment based tank system selection
4.2.1 General
The type of tank system shall be selected based on a risk assessment.
Risks inside and outside the plant shall be considered.
NOTE 1 See Annex F.
The materials of the main components, steel or concrete, and design details, e.g. the inlet/outlet, elevated
or grade level foundation and protection systems, shall be selected so that sufficient information is
available for the risk assessment.
The risk assessment shall demonstrate that the risks to property and life are acceptable, both inside and
outside the facility boundary.
NOTE 2 Risk management for the tank system already in service is outside of the scope of this document.
4.2.2 Site selection
Before identification of hazards can be carried out, the site shall be selected. In general, the storage tank
system shall be placed such that the pipe connections to the receiving and supply sources are as short as
possible. However, other requirements e.g. local regulations and safety distances (adjacent installations
and plant boundaries), site and soil
...
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